30D Noise Test Results

[Booswalia]

Since my other thread seems to be morphing into something else, I thought I would start a new one....

These are screen captures taken from FastStone Image Viewer. It lets you compare multiple images.
I used a shutter cable for all shots.
The first one was taken at ISO 250, 1/1000 sec. @ f7.1, f8, and f9. I used my 400mm f5.6 L lens.

http://www.sonnys.ca/freds/400mm-iso250b.jpg

Looking at these I thought noise was the least of my worries. It looks very soft. Here is another portion of the same three exposures.

http://www.sonnys.ca/freds/400mm-iso250.jpg

....so I went back out and took a few more shots with my 17-40mm lens.
taken at ISO 250, 1/500 sec. @ f10, f11, and f13.

http://www.sonnys.ca/freds/17-40-iso250.jpg

Any more thoughts.

[Hermeto]

There is no noise worth mentioning in any of these shots, IMHO..
What exactly are you trying to prove?

[jjmucker]

i cant see any noise either in those, and thats cropped right in too.
i bet if you were to print those pictures out they would look good. i dont think there is anything wrong with your 30D.

any camera will have noise (even at iso 100) if you start cropping way in like that. post those pics with no cropping so we can see how they look.

[jjmucker]

heres a pic from today and a crop. the full image looks perfect and will probably look good printed in terms of no noise,
but if your gonna crop heavily in then of course you will see noise.
F2.8 ISO 3200

this was converted from raw to jpg using DPP and had NR set to on in the preferences before converting

[Palladium]

IMPO - noise is a function of exposure.

nail exposure = less noise

[adas]

Shirley, you didn't mention where you focused on these images. First image in each set looks way too soft, and considering it was taken at f/7.1, that's pretty bad if the active focus point was aimed at what we see on these crops.

[Booswalia]

Hi Adas,
Thanks for commenting. I was focused on the metal bird but really the whole thing should have been in focus. Here's a capture of the full image @ f7.1
I'm concerned now that my 400mm is not a good copy.

http://www.sonnys.ca/freds/full.jpg

[cdifoto]

Post a crop of the tail. Even at f/7.1 there isn't much DOF on a 400mm lens.

[rabidcow]

I don't get it. You were testing noise by changing the aperture? What was the original plan with these tests?

[Permagrin]

I can see that the bottom right corner is sharp as a tack. So either it is front focusing or the focus was just missed on this shot.

[adas]

I don't get it. You were testing noise by changing the aperture? What was the original plan with these tests?

This test was suggested by someone else in another thread because she was consistently getting soft images on wich then she had to apply extra sharpening to pull out some detail, thus increasing the noise.
Basically, the test wanted to show that the camera can produce sharp images, by closing the aperture more.
Personally, I don't really like this test as it's not conclusive at all.

You need to do a focus test on a focus chart at widest aperture to see if the camera focus is spot on. Read this:
http://photo.net/learn/focustest/

[rabidcow]

This test was suggested by someone else in another thread because she was consistently getting soft images wich then she had to apply extra sharpening to pull out some detail, thus increasing the noise.
Basically, the test wanted to show that the camera can produce sharp images, by closing the aperture more.


I see...but this really does nothing for you because as you close off the aperture you are letting less light in and this results in an improper exposure so therefore there will be more noise...If you changed the shutter speed to compensate for your aperture shift this might prove more useful.

[wcl4]

Even with a tripod, 1/1000th sec 400mm on a 30D, you can get camera shake. I look at the left most picture, and to me that slight motion blur is indicative of the shake. The cloth just looks OOF and at the wrong plane to be sharp. Secondly, the wood on the right side of the frame looks pretty sharp, but wood is not a good test. As CDI says, 7.1 is not much DOF on a 400mm lens.

The shots taken with the 17-40 look soft to me as well. This along with the 400 shots makes me wonder where you're focusing or if you have a body front/back focus thing going on. Are there shots you're happy with taken with other lenses? If so, then the front/back thing can be discounted.

And lastly, as for the noise, that looks fine to me.

[Booswalia]

I read the article at photo.net and tried a test of my own. Here are the results...

This one was taken using a 60mm EFS f2.8
http://www.sonnys.ca/freds/focus60mm2.8.jpg

This one was taken with the 400mm f5.6. Obviously the test doesn't suit when shooting from 15 ft. away.
http://www.sonnys.ca/freds/focus400mm5.6.jpg

[adas]

It seems that the focus is pretty much spot on.
Though the 400 image looks a bit softer.
Are these 100% crops? If not, could you post a link to the original size of the 400 f/5.6 test? People here who have this lens will tell you if the sharpness is acceptable.

[Booswalia]

Sure, I'll post the original this evening after work.
Thanks for all your help on this.

[Booswalia]

Here is the original jpg image.
I cropped of the unnecessary edges off and changed it to black and white.
http://www.sonnys.ca/freds/400mmfullsize.jpg
I've only had this lens for about a month and would sure love to know if it's not up to the standard that it should be.

[baboymo]

I suggest closing this thread. There's nothing wrong with your lens.

As far as the noise is concerned, noise increased in the shadow area because when you stopped down your aperture for each shot you didn't lower your shutter speed accordingly, thus creating underexposure...which equals more noise.

[Booswalia]

I normally shoot using aperture priority.
The issue now is whether or not my 400 is soft or not. I would appreciate a few other opinions before closing the thread, if that's okay.

[Fernando]

I normally shoot using aperture priority.
The issue now is whether or not my 400 is soft or not. I would appreciate a few other opinions before closing the thread, if that's okay.

The key to controlling noise is getting the exposure right. What a couple other posters have noted is correct. As you stopped down you didn't change the shutter speed. No way, in that case, for your exposure to be right. The increase in noise you see as you stop down is a function of the exposure getting worse, not something wrong with the camera or sensor.

Of course I'm just a noob...that reads a lot.

-F

[Booswalia]

I give up.

[S.Horton]

OP - Your lens is fine.

Try the lens in broad daylight, IS on, frontlit subject, center-point AF only.

Having said that, I think I know how you feel, because you just paid over $1K for that lens and you expected it to be fantastic immediately, all the time, every time.

What you'll find is that in lower light, the lens does get a touch soft. When things look too soft, it is probably camera shake, so try monopod/tripod at 400mm.

BTW, one of your shots is sharp; it focused somewhere you didn't expect.